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Effects of Hypoxia Severity on Muscle Oxygenation Kinetics Using Statistical Parametric Mapping During Repeated Treadmill Sprints

Clint Hansen, Franck Brocherie, Grégoire P. Millet, and Olivier Girard

Repeated-sprint ability (RSA) entails executing brief (<30 s) maximal efforts with incomplete (<60 s) recovery intervals. 1 Near-infrared spectroscopy (NIRS) research has pinpointed the significance of oxidative metabolism and muscle oxygenation capacity as crucial determinants of RSA. 2 , 3

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Effects of High-Intensity Inspiratory Muscle Warm-Up on High-Intensity Exercise Performance and Muscle Oxygenation

Jun Koizumi and Toshiyuki Ohya

oxygenation have shown that IMW improves muscle oxygen tissue saturation during submaximal exercise, 12 but does not have a positive effect on muscle oxygenation during high-intensity or maximal effort exercise. 11 , 13 , 14 In many previous studies, IMW protocols were used that involved moderate

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New Zealand Blackcurrant Extract Enhances Muscle Oxygenation During Forearm Exercise in Intermediate-Level Rock Climbers

Simon Fryer, Craig Paterson, Ian C. Perkins, Chris Gloster, Mark E.T. Willems, and Julia A. Potter

oxygenation) are important for forearm endurance performance in climbers. One way to enhance blood flow and muscle oxygenation, and thus forearm performance, may be by intake of polyphenol ergogenic aids, such as anthocyanin-rich blackcurrant ( Kähkönen et al., 2003 ). Anthocyanins and anthocyanin

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Effects of Active and Passive Recovery on Muscle Oxygenation and Swimming Performance

Ade B. Pratama and Tossaporn Yimlamai

associated with an impairment of subsequent swimming performance. 4 However, the measurement of blood lactate concentration is invasive and may not practical in the field-based setting. Recently, the near-infrared spectroscopy (NIRS) has become widely used to assess noninvasively skeletal muscle oxygenation

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Muscle Oxygenation Rather Than VO2max as a Strong Predictor of Performance in Sprint Canoe–Kayak

Myriam Paquette, François Bieuzen, and François Billaut

metabolism in shorter canoe–kayak events. The availability of affordable and portable near-infrared spectroscopy (NIRS) monitors has increased accessibility to muscle oxygenation measures during exercise. 8 Only 2 studies have investigated muscle oxygenation in canoe–kayak athletes. 9 , 10 Junior male

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Acute Effects of Dietary Nitrate on Exercise Tolerance, Muscle Oxygenation, and Cardiovascular Function in Patients With Peripheral Arterial Disease

Cindy M.T. van der Avoort, Luc J.C. van Loon, Lex B. Verdijk, Paul P.C. Poyck, Dick T.J. Thijssen, and Maria T.E. Hopman

walking time) in patients with PAD. Secondary aims included investigation on plasma nitrate and nitrite concentrations, muscle oxygenation (assessed with near-infrared spectroscopy [NIRS]), blood pressure, and arterial stiffness (as measured with pulse wave velocity [PWV]). We hypothesized that elevation

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Effects of Ultratrail Running on Skeletal-Muscle Oxygenation Dynamics

Gianluca Vernillo, Alfredo Brighenti, Eloisa Limonta, Pietro Trabucchi, Davide Malatesta, Grégoire P. Millet, and Federico Schena

Purpose:

To quantify changes in skeletal-muscle oxygenation and pulmonary O2 uptake (V̇O2) after an extreme ultratrail running bout.

Methods:

Before (PRE) and after (POST) the race (330-km, 24000 D±), profiles of vastus lateralis muscle oxygenation (ie, oxyhemoglobin [O2Hb], deoxyhemoglobin [HHb], and tissue oxygenation index [TOI]) and V̇O2 were determined in 14 athletes (EXP) and 12 control adults (CON) during two 4-min constant-load cycling bouts at power outputs of 1 (p1) and 1.5 (p1.5) W/kg performed in randomized order.

Results:

At POST, normalized [HHb] values increased (p1, +38.0%; p1.5, +27.9%; P < .05), while normalized [O2Hb] (p1, –20.4%; p1.5, –14.4%; P < .05) and TOI (p1, –17.0%; p1.5, –17.7%; P < .05) decreased in EXP. V̇O2 values were similar (P > 0.05). An “overshoot“ in normalized [HHb]:V̇O2 was observed, although the increase was significant only during p1.5 (+58.7%, P = .003). No difference in the aforementioned variables was noted in CON (P > .05).

Conclusions:

The concentric and, particularly, the eccentric loads characterizing this extreme ultratrail-running bout may have led to variations in muscle structure and function, increasing the local muscle deoxygenation profile and the imbalance between O2 delivery to working muscles and muscle O2 consumption. This highlights the importance of incorporating graded training, particularly downhill bouts, to reduce the negative influence of concentric and severe eccentric loads to the microcirculatory function and to enhance the ability of runners to sustain such loading.

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Effects of Vascular Occlusion on Surface Electromyography and Muscle Oxygenation during Isometric Contraction

Eiji Yamada, Takashi Kusaka, Satoshi Tanaka, Satoshi Mori, Hiromichi Norimatsu, and Susumu Itoh

Objective:

To investigate changes in motor-unit activity and muscle oxygenation (MO) during isometric contraction with and without vascular occlusion using surface electromyography (EMG) and near-infrared spectroscopy.

Design and Setting:

MO and EMG of the right vastus medialis muscle were measured during isometric contraction at 30%, 50%, and 70% maximal voluntary contraction (MVC), with and without vascular occlusion.

Participants:

6 healthy men.

Results:

Integrated EMG (IEMG) and mean power frequency were significantly higher with vascular occlusion at 30% and 50% MVC. MO reduction at each load was significantly lower with vascular occlusion. A significant positive correlation was found between IEMG and changes in MO level under both conditions.

Conclusions:

These results suggest that oxygen supply to active muscles was impaired by occlusion and that type II fibers were then preferentially recruited, which suggests that hypertrophy occurs in low-intensity exercise in patients with limitations resulting from advanced age, pain, or postsurgery limitation.

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Performance, Metabolic, and Neuromuscular Consequences of Repeated Wingates in Hypoxia and Normoxia: A Pilot Study

Naoya Takei, Jacky Soo, Hideo Hatta, and Olivier Girard

-out” efforts with near complete recovery (4.5 min), 8 accompanying metabolic and neuromuscular adjustments were not determined. We aimed to compare the magnitude and time course of performance alterations, vastus lateralis muscle oxygenation trends, and interplay between central and peripheral neuromuscular

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Can Hyperoxic Preconditioning in Normobaric Hypoxia (3500 m) Improve All-Out Exercise Performance in Highly Skilled Skiers? A Randomized Crossover Study

David Morawetz, Tobias Dünnwald, Martin Faulhaber, Hannes Gatterer, Lukas Höllrigl, Christian Raschner, and Wolfgang Schobersberger

ambulance (Dr. Müller Gerätebau, Freital, Germany). A hyperemic ear lobe ointment was used to improve blood flow. Near-Infrared Spectroscopy An NIRS device (Moxy, Muscle Oxygen Monitor, Hutchinson, MN) was used to obtain information on muscle oxygenation (SmO 2 ) and total hemoglobin content (THb; density